Study Evaluating the Safety,Tolerability and Efficacy of PF-04360365 in Adults With Probable Cerebral Amyloid Angiopathy

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Cerebral Amyloid Angiopathy (CAA) is a condition caused by the build-up of a protein called amyloid, predominantly Aβ40, within the walls of brain blood vessels, especially those blood vessels in the occipital lobe of the brain. Probable CAA may be defined as two or more hemorrhages in the brain cortex in individuals 55 years of age or older. This study will examine the study drug (PF-04360365) vs. placebo (saline) at 10 mg/kg - Day 1 and the maintenance dose of the study drug (PF-04360365) vs. placebo (saline) at 7.5mg/kg on Days 30 and 60. Subjects will be followed for 6 months after receiving the last dose of study medication.

Change From Baseline to Day 2 in Cerebrovascular Reactivity as Measured by the Slope (Amplitude Over Time to Peak) From Visual Task-evoked Functional Magnetic Resonance Imaging (fMRI) [ Time Frame: Baseline, Day 2 ]

Blood Oxygen Level Dependant (BOLD) fMRI was performed at Screening (Baseline) and on Days 2 and 90. During each of these sessions, BOLD fMRI images were acquired in rapid succession as a flashing radial black and white checkerboard was presented alternately with a gray screen. This well established visual stimulus is known to produce a reliable increase in BOLD fMRI signal within the visual cortex region of the occipital lobe. The time course of the BOLD fMRI signal was used to assess the vascular reactivity. Imaging sites also acquired cerebral blood flow data using Arterial Spin Labeled (ASL) scans at Screening and on Days 2 and 90. A standard T1-weighted image was also acquired to aid image analysis. All efficacy scans were analyzed centrally. Geometric means are presented in the original scale and standard errors (SE) are presented in logarithmic (log e) scale.

Change From Baseline to Day 90 in Cerebrovascular Reactivity as Measured by the Slope (Amplitude Over Time to Peak) From Visual Task-evoked fMRI [ Time Frame: Baseline, Day 90 ]

BOLD fMRI was performed at Screening (Baseline) and on Days 2 and 90. During each of these sessions, BOLD fMRI images were acquired in rapid succession as a flashing radial black and white checkerboard was presented alternately with a gray screen. This well established visual stimulus is known to produce a reliable increase in BOLD fMRI signal within the visual cortex region of the occipital lobe. The time course of the BOLD fMRI signal was used to assess the vascular reactivity. Imaging sites also acquired cerebral blood flow data using ASL scans at Screening and on Days 2 and 90. A standard T1-weighted image was also acquired to aid image analysis. All efficacy scans were analyzed centrally. Geometric means are presented in the original scale and SEs are presented in log e scale.

Secondary Outcome Measures :

Change From Baseline to Day 2 and Day 90 in Cerebrovascular Reactivity as Measured by the Time to Peak From Visual Task-evoked fMRI [ Time Frame: Baseline, Day 2, Day 90 ]

BOLD fMRI was performed at Screening (Baseline) and on Days 2 and 90. During each of these sessions, BOLD fMRI images were acquired in rapid succession as a flashing radial black and white checkerboard was presented alternately with a gray screen. This well established visual stimulus is known to produce a reliable increase in BOLD fMRI signal within the visual cortex region of the occipital lobe. The time course of the BOLD fMRI signal was used to assess the vascular reactivity. Imaging sites also acquired cerebral blood flow data using ASL scans at Screening and on Days 2 and 90. A standard T1-weighted image was also acquired to aid image analysis. All efficacy scans were analyzed centrally. Geometric means are presented in the original scale and SEs are presented in log e scale.

Change From Baseline to Day 2 and Day 90 in Cerebrovascular Reactivity as Measured by the Amplitude From Visual Task-evoked fMRI [ Time Frame: Baseline, Day 2, Day 90 ]

BOLD fMRI was performed at Screening (Baseline) and on Days 2 and 90. During each of these sessions, BOLD fMRI images were acquired in rapid succession as a flashing radial black and white checkerboard was presented alternately with a gray screen. This well established visual stimulus is known to produce a reliable increase in BOLD fMRI signal within the visual cortex region of the occipital lobe. The time course of the BOLD fMRI signal was used to assess the vascular reactivity. Imaging sites also acquired cerebral blood flow data using ASL scans at Screening and on Days 2 and 90. A standard T1-weighted image was also acquired to aid image analysis. All efficacy scans were analyzed centrally. All values are presented in log e scale.

Change From Baseline to Day 2 and Day 90 in Cerebrovascular Reactivity as Measured by the Time to Return to Baseline From Visual Task-evoked fMRI [ Time Frame: Baseline, Day 2, Day 90 ]

BOLD fMRI was performed at Screening (Baseline) and on Days 2 and 90. During each of these sessions, BOLD fMRI images were acquired in rapid succession as a flashing radial black and white checkerboard was presented alternately with a gray screen. This well established visual stimulus is known to produce a reliable increase in BOLD fMRI signal within the visual cortex region of the occipital lobe. The time course of the BOLD fMRI signal was used to assess the vascular reactivity. Imaging sites also acquired cerebral blood flow data using ASL scans at Screening and on Days 2 and 90. A standard T1-weighted image was also acquired to aid image analysis. All efficacy scans were analyzed centrally. All values are presented in log e scale.

Change From Baseline in Concentration of Total Plasma Amyloid Beta (AB) [ Time Frame: Baseline, 8 hours post dose on Day 1, Day 2, Day 30, 90 and 240 ]

Cerebral amyloid angiopathy (CAA) is caused by the progressive deposition of amyloid, predominantly AB40, within the walls of cerebral blood vessels with a predisposition for the vessels of the occipital lobe. As such, it is of interest to investigate the effect of PF-04360365 on AB concentrations. AB1-x and AB1-40 were investigated.

Number of Participants With Brain Structural Magnetic Resonance Imaging (sMRI) Abnormalities [ Time Frame: Baseline/Screening, Day 15, Day 45, Day 90, ]

Brain sMRI abnormalities included cerebral edema and total infarcts (including cortical infarcts, white matter infarcts, and subcortical gray matter infarcts). "Total infarcts" is the total number of participants with at least 1 type of infarct.

The Montreal Cognitive Assessment (MoCA) was used as a safety outcome measure to assess any changes in cognition. The MoCA is a 1-page 30-point test administered in approximately 10 minutes. The MoCA assessed short term memory, visuospatial abilities, multiple aspects of executive functions, attention, concentration, working memory, and language, as well as orientation to time and place. The total scale ranges from 0 to 30, with lower numbers indicating lower cognition performance.

Number of Participants With All Causality and Treatment-related Treatment-emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), and Discontinuations Due to Adverse Events (AEs) [ Time Frame: Baseline up to Day 240 ]

An AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. AEs comprised both SAEs and non-SAEs. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent adverse events (TEAEs) were defined as newly occurring AEs or those worsening after first dose.

Number of Participants With Laboratory Abnormalities [ Time Frame: Baseline up to Day 240 ]

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Ages Eligible for Study:

55 Years to 90 Years (Adult, Senior)

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Patients diagnosed with probable CAA using the Boston criteria; with no clinical cognitive impairment